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2007: Exploring the Inner Space of the Celebes

Outta Gas

Focus Maximum Number of Students 30

Grade Level Key Words 9-12 (Chemistry/Physics) Celebes Sea Focus Question Gas laws How can Boyle’s Law, Charles’ Law, Gay-Lussac’s Law, Henry’s Law, and Dalton’s Law be used to Boyle’s Law predict the behavior of gases used in SCUBA div- Charles’ Law ing? Gay-Lussac’s Law Henry’s Law Learning Objectives Dalton’s Law Students will define Boyle’s Law, Charles’ Law, Gay-Lussac’s Law, Henry’s Law, and Dalton’s Law. Worksheet Mathematics Students will use Boyle’s Law, Charles’ Law, Gay- Lussac’s Law, Henry’s Law, and Dalton’s Law to Background Information solve practical problems related to SCUBA diving. Indonesia is well-known as one of Earth’s major centers of biodiversity. Although Indonesia cov- Materials ers only 1.3 percent of Earth’s land surface, it  “Blue Water Diving Worksheet,” one copy for includes: each student or student group • 10 percent of the world’s flowering plant species; Audio/Visual Materials • 12 percent of the world’s mammal species; None • 16 percent of all reptile and amphibian species; and Teaching Time • 17 percent of the world’s bird species. One or two 45-minute class periods plus time for students to complete worksheet In addition, together with the Philippines and Great Barrier , this region has more species Seating Arrangement of fishes, corals, mollusks, and crustaceans than Classroom style any other location on Earth.

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) Focus: Gas laws oceanexplorer.noaa.gov

What, exactly, is meant by biodiversity, and why of the ocean. Note that the term “midwater” as is it important? The term “biodiversity” is usually used here includes the entire water column, but understood to include variety at several levels: the same term has also been used to refer to • variety of ecosystems: high biodiversity sug- only part of the water column. Scientists often gests many different ecosystems in a given divide the ocean water column into three zones: area; the “epipelagic zone” (also called the “sunlit” or • variety of species: high biodiversity suggests “euphotic” zone) from the surface to a depth of many different species in a given area; about 200 m; the “mesopelagic zone” between • variety of interactions between species; and 200 m and 1100 m; and the “bathypelagic • variety within species (genetic diversity): high zone,” which is deeper than 1100 m. biodiversity suggests a relatively high level of genetic variety among individuals of the same “Plankton” is a general term for organisms that species. drift or swim weakly in midwater environments, and includes plants (phytoplankton) as well as A simple definition of biodiversity could be “The animals (zooplankton). Phytoplankton include variety of all forms of life, ranging in scale from major primary producers in aquatic food webs, genes to species to ecosystems.” and zooplankton are often the primary consum- ers that are a key link in transferring energy to Biodiversity is important to humans because our other consumers in these food webs. Despite their survival depends upon many other species and importance, many types of zooplankton are not ecosystems. Some examples of our dependence well-understood. This is partially because many on biodiversity include: zooplankton are fragile, jelly-like creatures that • fresh air containing ; are easily damaged by nets and other devices • clean water; that are traditionally used to collect midwater • productive soils; animals for study. Scientists participating in the • food, medicines and natural products; 2007: Exploring the Inner Space of the Celebes • natural resources that provide the basis for Sea Expedition plan to use techniques known as human economies; and blue-water diving to observe and collect fragile • natural beauty that improves our quality of midwater animals. life. (adapted from the Biodiversity Project, http://www. Diving in the open ocean is quite different from biodiversityproject.org/bdimportant.htm) nearshore diving, because there are no objects for visual reference, and it is very easy for divers Quite a lot is known about Indonesia’s terres- to become disoriented. Blue-water diving tech- trial and shallow-water ecosystems. But scientific niques involve a system of lines and floats to cre- knowledge and understanding of midwater ate visual reference points, as well as procedures ocean communities is generally sketchy, and that help keep divers in touch with each other. many midwater animals have not been studied One diver (called the “safety diver”) holds an at all – even though the midwater ocean environ- aluminum “trapeze,” and descends to the desired ment is our planet’s largest ecosystem. Midwater depth along a weighted line attached to a sur- animals range from microscopic zooplankton to face float. Other divers are attached to safety the largest animals on Earth, provide a major lines that clip onto the trapeze. This system allows source of nutrition for benthic (bottom) communi- the safety diver to keep track of the “working” ties, and are an important link in the transfer of divers who are free to concentrate on research energy and materials from the top to the bottom tasks.

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) oceanexplorer.noaa.gov Focus: Gas laws

that they are familiar with the system of units to Even with such specialized techniques, divers be used. The appropriate SI units are: who use self-contained underwater • pressure in pascals (Pa) apparatus (SCUBA) still must be aware of be • volume in cubic meters (m3) behavior of gases under pressure, and how the • number of molecules in moles (mol) basic gas laws apply to SCUBA diving. In this • in degrees Kelvin (°K) lesson, students will be introduced to Boyle’s Law, • R has a value of 8.314 joules per mole per Charles’ Law, Gay-Lussac’s Law, Henry’s Law, degree Kelvin (j/mol/°K) and Dalton’s Law, and how these laws affect SCUBA divers. However, other units are commonly used when gas laws are applied to SCUBA diving: Learning Procedure • pressure in pounds per square inch (psi) or 1. To prepare for this lesson, review the introduc- atmospheres (atm); 1 atm = 101,325 Pa = tory essays for the 2007: Exploring the Inner 14.7 psi Space of the Celebes Sea Expedition at http:// • volume in liters or cubic feet; 1 l = 10-3 m3; 1 oceanexplorer.noaa.gov/explorations/07philippines/. You can ft3 = 28.3 l view many images of planktonic organisms at • R has a value of 0.082 L · atm/mol/°K http://www.imagequest3d.com/catalogue/larvalforms/, but be aware of copyright restrictions posted on the Students should also understand that when the Web site. Ideal Gas Law is used to describe the behavior of a fixed quantity of gas, the equation can be If students are not familiar with the fundamental written as

concepts embodied in Boyle’s Law, Charles’ P1 • V1 = P2 • V2 Law, Gay-Lussac’s Law, Henry’s Law, and T1 T2 Dalton’s Law, you may want to introduce these concepts using activities described in the “It’s Where P1, V1, and T1 are the initial pressure, the Law!” lesson. volume, and temperature, respectively, and P2,

V2, and T2 are the pressure, volume, and tem- 2. Briefly introduce the 2007: Exploring the Inner perature after one or more of these variables Space of the Celebes Sea Expedition, focusing has changed. on the importance of midwater animals and why these animals have not been well-studied. 4. Provide each student or student group with a You may want to briefly describe the problems copy of “Blue Water Diving Worksheet.” When of SCUBA diving in the open ocean and some students have solved the Worksheet problems, of the blue-water diving techniques used to lead a discussion of their answers. The follow- overcome these problems. ing points should be included:

3. Discuss the Ideal Gas Law (P • V = n • R • (1) Boyle’s Law states that the product of the T). Students should recognize that this “law” volume and pressure of a gas held at a con- describes the interaction between four vari- stant temperature is equal to a constant (PV ables: pressure, volume, number of gas mole- = k). So, if the pressure of the gas doubles, cules, and temperature. Be sure students under- the volume will be decreased by half; and stand that “pressure” refers to absolute pressure if the volume of a gas doubles, the pressure (in the case of SCUBA diving, the combined must decrease by half. pressure of the atmosphere and water), and

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) Focus: Gas laws oceanexplorer.noaa.gov

(2) Charles’ Law states that the volume of a of oxygen in the can given amount of gas is directly propor- cause loss of known as “deep- tional to the Kelvin temperature provided water blackout.” the amount of gas and the pressure remain fixed. (8a) When she takes a breath at 20 m, the air in her lungs has a pressure of 3 atm. (3) Gay-Lussac’s Law states that for a fixed amount of gas (fixed number of moles) at a (8b) The volume of air in her lungs when she fixed volume, the pressure of the gas is pro- takes a deep breath at 20 m is 5 liters. portional to the temperature. (8c) If she took a deep breath and returned to (4) Henry’s Law states that the mass of a gas the surface while holding her breath, the which dissolves in a volume of liquid is pro- volume of air in her lungs would expand by portional to the pressure of the gas. a factor of three (pressure changes from 3 atm to 1 atm). This would cause the alveoli (5) Dalton’s Law states that the pressure exerted and small capillaries in her lungs to rupture, by a mixture of gases is equal to the sum of causing massive bleeding and probably the that would be exerted by the death. gases individually. (9) Since (6) For every ten meters of depth, water pres- 1 ft3 = 28.3 l sure increases by approximately one atmo- sphere (101,325 Pa). the filled tank contains

(7a) Absolute pressure changes from 1 atm at 80 ft3 = 80 • 28.3 l = 2,264 l the surface to 3 atm at 20 m. So, Since

P1 • V1 = P2 • V2 P1 • V1 = P2 • V2

T1 T2 T1 T2

1 atm • 5.0 l = 3 atm • V2 assuming constant temperature, at 30 m depth, the gas in the tank would have a vol- Tconstant Tconstant ume of

V2 = 5 l ÷ 3 = 1.7 l 1 atm • 2,264 l = 4 atm • V2

(7b) Since the partial pressure of oxygen Tconstant Tconstant increases by three, Henry’s Law predicts that

the amount of dissolved oxygen will also V2 = (2,264 l) ÷ 4 = 566 l increase by three. and this volume is equivalent to (7c) As returns to the surface, the absolute pressure changes from 3 atm to 1 (566 l) ÷ (0.5 l/breath) = 1,132 breaths atm, so the partial pressure will be reduced to one-third. This rapid decrease in the

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) oceanexplorer.noaa.gov Focus: Gas laws

(10) Once again, (3.49 atm) • (10 m/atm) = 34.9 m

P1 • V1 = P2 • V2 12. According to Henry’s Law, the mass of a T1 T2 gas that dissolves in a volume of liquid is Remembering to use absolute pressure, proportional to the pressure of the gas. This means that as a diver descends to greater P1 = 3,000 psi + 14.7 psi = 3,015 psi depths, progressively more breathing gases and will dissolve in her blood. When she returns to the surface, these gases become less P2 = 3,000 psi + 0.2 • 3,000 psi = 3,600 psi soluble because the external pressure is reduced, and the gases begin to diffuse out Also, remembering to convert temperature to of her blood. If the ascent is too rapid, bub- degrees Kelvin bles can form in the blood. If the bubbles are large enough they may block important 20°C = 20 + 273 = 293°K blood vessels causing pain, paralysis, or death. sickness in divers usu- Since the volume of the tank is constant, ally involves bubbles of . Oxygen in air does not form such bubbles because much of the oxygen dissolved in a diver’s 3,015 psi • Vconstant = 3,600 psi • Vconstant blood is quickly bound by hemoglobin, and normal further reduces blood 293°K T2 oxygen . So The Bridge Connection www.vims.edu/bridge/ – In the “Site Navigation” menu T2 = (3,600 psi • 293°K) ÷ 3,015 psi = 350°K on the left, click on “Ocean Science Topics,” then which is equivalent to a Celsius temperature of “Human Activities,” then “Recreation” for links to 350 - 273 = 77°C resources about SCUBA diving.

(11) According to Dalton’s Law, the pressure The “Me” Connection exerted by a mixture of gases is equal to the Have students write a brief essay describing how sum of the pressures that would be exerted one or more of the gas laws might be directly rel- by the gases individually. So if the partial evant to their own lives. pressure of nitrogen is 3.5 atm, the total pressure of the breathing air is Connections to Other Subjects Biology, Mathematics 3.5 atm ÷ 0.78 = 4.49 atm Assessment Since this is absolute pressure, Discussions and written responses (if assigned) provide opportunities for assessment. 4.49 atm absolute = 1 atm air pressure + 3.49 atm water pressure Extensions 1. Visit oceanexplorer.noaa.gov to keep up to date with Since pressure increases by about 1 atm for the latest 2007: Exploring the Inner Space of every 10 m depth, the equivalent depth is the Celebes Sea Expedition discoveries, and to  2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) Focus: Gas laws oceanexplorer.noaa.gov

find out what researchers are learning. In this activity, students will describe the charac- teristics of plankton; develop abilities necessary 2. Visit the Newton’s Apple Teacher Guide to do scientific inquiry; test the effects of different for SCUBA diving at http://www.newtonsapple.tv/ salinity and temperature on the vertical movement TeacherGuide.php?id=1673. of a model of a planktonic organism; and calcu- late the velocity of the plankton model. 3. For another activity involving graphing, calcula- tors, Henry’s Law, and “the bends,” see http:// How Diverse is That? [http://www.oceanexplorer. dwb.unl.edu/calculators/pdf/Bends.pdf noaa.gov/explorations/03windows/background/education/media/ 03win_hdiverse.pdf] (6 pages, 552k) (from the 2003 Multimedia Learning Objects Windows to the Deep Expedition) http://www.learningdemo.com/noaa/ – Click on the links to Lessons 8 and 12 for interactive multimedia Focus: Quantifying biological diversity (Life presentations and Learning Activities on Ocean Science) Currents and Food, Water, and Medicine from the Sea. In this activity, students will be able to discuss the meaning of “biological diversity” and will be able Other Relevant Lesson Plans from the Ocean Exploration to compare and contrast the concepts of “variety” Program and “relative abundance” as they relate to bio- Blinded By the Light!! [http://www.oceanexplorer. logical diversity. Given abundance and distribu- noaa.gov/explorations/02sab/background/edu/media/sab_blinded. tion data of species in two communities, students pdf] (6 pages, 460k) (from the Islands in the will be able to calculate an appropriate numeric Stream 2002: Exploring Underwater Oases indicator that describes the biological diversity of Expedition) these communities.

Focus: Physical Science – Absorption, Scattering, Where Is That Light Coming From? [http:// and Reflection of Light in the Deep Sea www.oceanexplorer.noaa.gov/explorations/04deepscope/back- ground/edu/media/WhereisLight.pdf] (PDF, 208Kb) (from In this activity, students will recognize that the col- the 2004 Operation Deep Scope Expedition) ors they see are a result of the reflection of light and that other colors of light are absorbed; pre- Focus: Bioluminescence dict what color an object will appear when light of different colors is shined upon it; predict what In this activity, students explain the role of lucifer- color(s) will be produced when different colors ins, luciferases, and co-factors in bioluminescence of light are mixed; and identify the three primary and the general sequence of the light-emitting colors and three secondary colors of light. process. Additionally, students discuss the major types of luciferins found in marine organisms, Drifting Downward [http://www.oceanexplorer.noaa. define the lux operon and discuss at least three gov/explorations/02sab/background/edu/media/sab_drifting.pdf] ways that bioluminescence may benefit deep-sea (6 pages, 464k) (from the Islands in the Stream organisms. Students give an example of at least 2002: Exploring Underwater Oases Expedition) one organism that actually receives each of the benefits discussed. Focus: Biology – Adaptations of planktonic organ- isms in the ocean

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) oceanexplorer.noaa.gov Focus: Gas laws

Other Links and Resources Content Standard F: Science in Personal and Social The Web links below are provided for informa- Perspectives tional purposes only. Links outside of Ocean • Personal health Explorer have been checked at the time of this • Science and technology in society page’s publication, but the linking sites may become outdated or non-operational over time. Ocean Literacy Essential Principles and Fundamental Concepts http://oceanexplorer.noaa.gov – Web site for NOAA’s Essential Principle 1. Ocean Exploration program The Earth has one big ocean with many features. Fundamental Concept h. Although the ocean is http://oceanexplorer.noaa.gov/gallery/livingocean/livingocean_coral. large, it is finite and resources are limited. html – Ocean Explorer photograph gallery Essential Principle 5. Hamner, W. M. 1975. Underwater observations of The ocean supports a great diversity of life and ecosystems. blue-water plankton: Logistics, techniques, Fundamental Concept c. Some major groups are and safety procedures for divers at sea. found exclusively in the ocean. The diversity of Limnology and 20:1045- major groups of organisms is much greater in the 1051; available online at http://aslo.org/lo/toc/ ocean than on land. vol_20/issue_6/1045.pdf. Fundamental Concept d. Ocean biology provides many unique examples of life cycles, adaptations http://www.imagequest3d.com/catalogue/larvalforms/ – Image and important relationships among organisms Quest 3-D Web site, featuring images of (such as symbiosis, predator-prey dynamics and numerous marine organisms; all images are energy transfer) that do not occur on land. copyrighted, but are still great to look at Fundamental Concept e. The ocean is three- dimensional, offering vast living space and http://www.pbs.org/wgbh/nova/lasalle/buoybasics.html – diverse habitats from the surface through the “ Basics” Web site from NOVA water column to the seafloor. Most of the living space on Earth is in the ocean. http://www.grc.nasa.gov/WWW/K-12/airplane/aboyle.html – Fundamental Concept f. Ocean habitats are Animated demonstration of Boyle’s Law defined by environmental factors. Due to interac- from NASA’s Glenn Research Center tions of abiotic factors such as salinity, tempera- ture, oxygen, pH, light, nutrients, pressure, sub- http://www.chemsoc.org/networks/learnnet/classic_exp.htm – The strate and circulation, ocean life is not evenly dis- Royal Society of Chemistry’s “Classic tributed temporally or spatially, i.e., it is “patchy.” Chemistry Experiments” Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while National Science Education Standards much of the ocean is considered a desert. Content Standard A: Science As Inquiry • Abilities necessary to do scientific inquiry Essential Principle 6. • Understandings about scientific inquiry The ocean and humans are inextricably interconnected. Fundamental Concept a. The ocean affects every Content Standard B: Physical Science human life. It supplies freshwater (most rain • Properties & changes of properties in matter comes from the ocean) and nearly all Earth’s oxy- gen. It moderates the Earth’s climate, influences our weather, and affects human health.

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) Focus: Gas laws oceanexplorer.noaa.gov

Fundamental Concept b. From the ocean we Fundamental Concept f. Ocean exploration is get foods, medicines, and mineral and energy truly interdisciplinary. It requires close collabora- resources. In addition, it provides jobs, supports tion among biologists, chemists, climatologists, our nation’s economy, serves as a highway for computer programmers, engineers, geologists, transportation of goods and people, and plays a meteorologists, and physicists, and new ways of role in national security. thinking. Fundamental Concept e. Humans affect the ocean in a variety of ways. Laws, regulations and Send Us Your Feedback resource management affect what is taken out We value your feedback on this lesson. and put into the ocean. Human development and Please send your comments to: activity leads to pollution (such as point source, [email protected] non-point source, and noise pollution) and physi- cal modifications (such as changes to beaches, For More Information shores and rivers). In addition, humans have Paula Keener-Chavis, Director, Education Programs removed most of the large vertebrates from the NOAA Ocean Exploration Program ocean. Hollings Marine Laboratory Fundamental Concept g. Everyone is responsible 331 Fort Johnson Road, Charleston SC 29412 for caring for the ocean. The ocean sustains life 843.762.8818 on Earth and humans must live in ways that sus- 843.762.8737 (fax) tain the ocean. Individual and collective actions [email protected] are needed to effectively manage ocean resourc- es for all. Acknowledgements This lesson plan was produced by Mel Goodwin, Essential Principle 7. PhD, The Harmony Project, Charleston, SC The ocean is largely unexplored. for the National Oceanic and Atmospheric Fundamental Concept a. The ocean is the last Administration. If reproducing this lesson, please and largest unexplored place on Earth—less than cite NOAA as the source, and provide the follow- 5% of it has been explored. This is the great ing URL: http://oceanexplorer.noaa.gov frontier for the next generation’s explorers and researchers, where they will find great opportuni- ties for inquiry and investigation. Fundamental Concept b. Understanding the ocean is more than a matter of curiosity. Exploration, inquiry and study are required to bet- ter understand ocean systems and processes. Fundamental Concept c. Over the last 40 years, use of ocean resources has increased signifi- cantly, therefore the future sustainability of ocean resources depends on our understanding of those resources and their potential and limitations. Fundamental Concept d. New technologies, sensors and tools are expanding our ability to explore the ocean. Ocean scientists are relying more and more on satellites, drifters, buoys, sub- sea observatories and unmanned submersibles.

 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) oceanexplorer.noaa.gov Focus: Gas laws

Blue Water Diving Worksheet

1. Define Boyle’s Law

2. Define Charles’ Law

3. Define Gay-Lussac’s Law

4. Define Henry’s Law

5. Define Dalton’s Law

6. How is water depth related to the pressure experienced by a free-swimming diver?

7. An experienced diver takes a deep breath at the surface, and rapidly swims to a depth of 20 m without SCUBA equipment.

(a) If the total volume of air in her lungs is 5.0 liters at the surface, what is the volume of air in her lungs at a depth of 20 m (assume the temperature remains constant)?

(b) According to Henry’s Law, what happens to the amount of dissolved oxygen in the diver’s blood at a depth of 20 m?

(c) As the diver returns to the surface, what happens to the partial pressure of oxygen in her lungs?

8. The same experienced diver decides to repeat her descent with SCUBA equipment.

(a) When she takes a breath at 20 m, what is the pressure of air in her lungs?

(b) What is the volume of air in her lungs when she takes a deep breath at 20 m?

(c) Suppose she suddenly realizes her air tank is almost empty. What would happen if she took a deep breath and returned to the surface while holding her breath?

9. The capacity of SCUBA tanks is often stated as “the amount of the tank will hold at its maximum rated service pressure.” “Amount” is typically stated as the equivalent volume at a pressure of 1.0 atm. So, if an 80 ft3 tank is filled to its rated pressure of 3,000 psi, the gas in the tank would have a volume of 80 ft3 at a pressure of 1.0 atm.

Suppose a diver has a SCUBA tank with a capacity of 80 ft3. If the tidal volume (the amount of air he breathes in or out during normal ) is 500 ml, how many breaths should he expect from his tank at a depth of 30 m?

10. Valves on SCUBA tanks should always be equipped with “burst disks” that rupture if the pressure inside the tank exceeds the tank’s pressure rating. Suppose a SCUBA tank is filled to its maximum rated pressure of 3,000 psi, and the tank has a “burst disk” that is designed to rupture if the pres- sure rises more than 20% above the tank’s rated pressure. The tank’s owner puts the filled tank into 2007: Exploring the Inner Space of the Celebes Sea – Grades 9-12 (Chemistry/Physics) oceanexplorer.noaa.gov Focus: Gas laws

the trunk of his car, then parks his car in a shadeless shopping mall. What temperature will cause the “burst disk” to rupture if temperature inside the dive shop where the tank was filled was 20°C?

11. Nitrogen narcosis (sometimes called “rapture of the deep”) is a state similar to that usually occurs in divers at depths greater than 30 m. To avoid nitrogen narcosis, some diving authorities recommend that divers should not be exposed to partial pressures of nitrogen above 3.5 atm absolute. Using this recommendation, what is the maximum safe depth for a diver breathing ordinary air (which contains about 78% nitrogen)?

12. How is Henry’s Law related to ? Why doesn’t oxygen in breathing air cause decompression sickness?